EXTRACTION and BIODEGRADATION OF BAOBAB (Adansonia digitata) SEEDS OIL BY FUNGI (Aspergillus niger)

Baobab (Adansonia digitata) seed oil was extracted using the soxhlet extractor in n-hexane at 60oC and some of its physical parameters determined. The oil was biodegraded using a Fungi (Aspergillus niger) between 25-30oC for 49 days. The pH and viscosity of the oil were measured as incubation period progressed. The result revealed a gradual decrease in pH but an increase in viscosity of the oil as the incubation time increases. It was opined that the decrease in pH could be due to the secretion of enzymes, and the subsequent breaking down of the substrates into smaller acidic molecules whereas, the increase in Viscosity could have been due to the assimilation of these molecules by the microorganisms which may have led to their growth and or increase in the population and the formation of long chain metabolites. The Fourier Transform Infrared determined showed shifts in the absorption bands of the functional groups such as carbonyl, hydroxyl, carboxylic and amide of the biodegraded oil. The GC - MS analysis showed the esterification of unsaturated carboxylic acid to 9-octadecanoic acid and the formation of 2-hydroxy-1, 3-propanediyl ester by the Aspergillus niger. Therefore, it was concluded that biodegradation of Adansonia digitata has taken place in 35 days. Keywords: Biodegradation, Seed oil, Aspergillus niger, Viscosity, Baobab (Adansonia digitata

Comparative Assessment of the Levels of Some Metal Ions in Soil Rhizosphere of Onion and Onion Bulb (Allium cepa l) Cultivated in Danbam Local Government Area: North East Nigeria

Authors: Elisha Karu*, Buhari Magaji, Aishatu Umar Maigari and Fauziyya Aliyu Jibo Received 11 February 2021/Accepted 22 March 2021 Levels of some metal ions (Cd2+, Pb2+, Cr3+, Mn2+ and Mg2+) in the soil rhizosphere and onion bulb were determined by spectroscopic techniques (Atomic Absorption Spectroscopy AAS, and UV-Visible Spectrophotometry). Comparative analysis of the results by the two techniques used shows that Cr, Cd, and Pb were not detected by atomic absorption spectrophotometer in both the soil rhizosphere and onion bulbs but Mn was detected at concentrations ranges of 9 – 12 ppm and 2 – 13 ppm in the soil and onion bulbs. Concentration of Mg2+ was observed to range 6 – 10 ppm and 7 -9 ppm in the soil and onion bulb respectively. Much lower concentrations were detected by the spectrophotometric determinations of Cd, Mn, and Pb in both the soil and onion bulb samples with Pb having the highest concentration (0.002 – 0.005 ppm) in the four study sites. Cr was not detected by any of the two techniques used

Biosynthesis of Zinc Oxide Nanoparticles Using Solenostemon Monostachyus Leaf Extract and its Antimicrobial Activity

Communication In Physical Sciences 2020 ,66(1) : 699-705 Received 24 August 2020/Accepted 07 September 2020 A simple and rapid biosynthesis of zinc oxide nanoparticles (ZnO NPs) obtained using Solenostemon monostachyus leaf extract. The ZnO NPs was characterised by UV-visible spectroscopy, scanning electron microscopy/Energy dispersed X-ray, Fourier Transform Infra-red and X-ray Diffraction techniques. The UV-visible spectrum showed a maximum absorption peak at 350 nm which is typical for ZnO NPs and was ascribed to the excitation of Surface Plasmon Resonance phenomenon. FTIR Spectroscopy revealed a broad peak around 3455 cm-1 which was attributed to OH stretching vibration (υOH) that is probably from alcohols, flavonoids and phenols. X-ray Diffraction studies were observed at 2θ = 11.1°, 13.8°, 16.7°, 25.1°, 28.9° and 44.0°. The X-ray spectrum indicated typical for crystalline nanoparticles. Calculated nano particle size was 23.06 nm and was within the literature range for nano zinc oxide. The synthesized NPs exhibited significant antibacterial activity against Escherichia coli and Staphylococcus aureus but exhibited moderate activity against Klebsiella pneumonia and Salmonella typhimurium. Significant antifungal activity was also observed against Aspergellus niger and Candida albican

Health Risk Assessment of Heavy Metals in Soil Rhizosphere and Onion Bulbs Cultivated in Danbam Farmlands, North East, Nigeria

Authors: Elisha Karu*, Buhari Magaji, Aishatu Umar Maigari and Fauziyya Aliyu Jibo Received: 24 June 2021/Accepted 05 July 2021 This study was conducted to determine the levels of heavy metals (Cd, Cr, Mn, and Pb) in soil rhizosphere and onion bulbs from four locations in the Danbam area of Bauchi State Spectrophotometry method were employed for the determination of the concentrations of the metals. The concentrations of all the heavy metals were found to be in the range 4.06 × 10-8 to 1.91 × 10-1 mg/kg which are below the permissible level (0.02, 500, and 0.3 mg/kg for Cd, Mn, and Pb respectively) set by FAO/WHO. The study also revealed that daily metal intake (DIM), hazard quotient (HQ), and hazard index (HI) were below unity and points to the nonexistence of potential public health. Calculated bioconcentration factors (BCF) suggested a higher concentration of heavy metal ions in the soil than in the onion bulbs and did not portray any risk to public healt